Method and apparatus for washing fruits and vegetables

ABSTRACT

One embodiment of the present invention includes an apparatus for washing a product with a fluid. The tank may receive a plurality of product, such as fruits and vegetables, into the fluid and be configured to receive a moving conveyor, having a first end, a second end, a first section, and a second section. The conveyor may have a plurality of protruding panels being structured and arranged on the conveyor to push the product through the fluid in the tank and to lift the product from the fluid in the tank to the second end of the conveyor. At least one first nozzle may be positioned substantially above the conveyor and configured to deliver the fluid onto the product as the product is pushed by the plurality of panels. The fluid delivered from the at least one first nozzle may rotate the product in the fluid in the tank.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to and is a continuation of U.S.patent application Ser. No. 11/181,960, now U.S. Pat. No. 7,467,638,filed Jul. 15, 2005, which is based on provisional patent ApplicationNo. 60/588,817, filed Jul. 15, 2004, the teachings of which are hereinincorporated by reference in their entirety for all purposes.

FIELD OF THE INVENTION

The present invention relates to preparing fruits and vegetables afterharvesting and, more particularly, to method and apparatus for washingfruits and vegetables.

BACKGROUND OF THE INVENTION

Prior to consuming or processing fruits and vegetables a thoroughwashing is required to remove dust, pesticides, and biologicalcontamination from the surface of the product. Bacteria that is notremoved or destroyed may not only cause spoilage of the fruit orvegetable, but may also cause serious illness. Dangerous pathogens, suchas Salmonella, E. coli, and Listeria, occur commonly in nature and underthe right circumstances can make there way through the commercial foodchain to the consumer.

Attempting to clean the fruit or vegetable by removing the products peelhas been shown to be unsuccessful in eliminating the problem. Peelingknives can transmit contaminants from the surface of the skin to cellsthat become exposed when the peel is removed. Blanching andpasteurization processes used in the freezing, canning, and dehydratingindustries do kill pathogens and thus minimize the food safety risk.However, these processes include thermal processing, which degradestexture, flavor, and nutritional value. As a result blanching andpasteurization processes fail as a suitable cleaning method when naturaltasting, high quality fruits and vegetables are desired.

Often, fruits and vegetables are submerged in a cleaning solution inorder to kill pathogens and remove dirt and other contaminants.Unfortunately, fruit and vegetables that float, such as apples, peaches,plums, and peppers, create difficulties during washing. The area mostsubject to contamination is the depression on top of the fruit where thestem connects because the fruit is oriented upwards when hanging on thetree forming a pocket that collects dust and harbors bacteria. Certainfruit, such as apples, tend to float stem up, making the depression onthe top of the fruit difficult to clean without special and costlyattention.

Traditionally, brush washers and flume washers are commonly used toclean produce yet both fail to adequately clean the dirtiest area of thefruit. Brush washers typically employ rotating bristles to scrub thesurface of the fruit or vegetable. Unfortunately, the rotating bristlesfail to penetrate into recesses, thus leaving the dirtiest area of thefruit or vegetable, such as the depression on an apple, untouched.

While flume washers attempt to immerse the fruit or vegetables, manyfloating fruits fail to be cleaned adequately. Bins of produce may bedumped into flumes and hydraulically conveyed to other processingequipment, such as sorters or peelers. Immersion of the product,typically occurring only when the fruit and vegetable is initiallydumped into the flume, often serves as the only washing step prior toprocessing. Many fruits, such as apples, and vegetables float with theirstem oriented upwards, out of the water. As a result of the limited andrandom contact with water, the flume washers also fail to adequatelyclean the dirtiest part of the fruit or vegetable.

To enhance the cleaning process, water sprays have been added to brushand/or flume washers. However, speed of travel and orientation of theproduct in a flume washer is not well controlled, making positivecontact by the sprays on all surfaces uncertain and sporadic. Brushwashers traditionally control product movement with greater accuracy,but the brushes themselves are inherently a sanitation issue. Dirt,foreign material, and organic matter often becomes packed or wedgedbetween the brush bristles, providing a natural growth medium forbacteria. This cohesive mixture hardens with time, is difficult toremove, and forms a barrier to chemical treatment, eventually resultingin expensive maintenance or replacement.

Antimicrobial agents, such as chlorine, ozone, chorine dioxide,peroxyacetic acid, and peroxide are added to wash water to reducebacteria population on the product and to control bacterial growth inthe wash water and on equipment surfaces. To achieve maximumeffectiveness and elimination of pathogens, product must be exposed tothe sanitizing solution for a given amount of time. A direct correlationexists between bacteria reduction and exposure time. Unfortunately,however, there is no precise means to control exposure time or to ensureuniform coverage of all product surfaces with brush and flume washers,making it difficult to ensure that minimum exposure times have been met.Therefore, a thorough and reliable washing process is a critical part ofensuring fresh-cut ready-to-eat fruits and vegetables are safe for theconsumer.

Therefore, there is a need for a method and apparatus for washing fruitsand vegetables that float with precise control of exposure time to thecleaning solution, and with precise product movement to ensure completesolution exposure to all product surfaces.

SUMMARY OF THE INVENTION

One embodiment of the present invention includes an apparatus forwashing a product with a fluid. The apparatus may include a tank a firstend and a second end and configured to contain the fluid at apredetermined height. The tank may receive a plurality of product intothe fluid and be configured to receive a moving conveyor, having a firstend, a second end, a first section, and a second section. The firstsection and the first end of the conveyor may be substantially submergedin the fluid in the tank with the first end of the conveyor beingsubstantially adjacent to the first end of the tank. Further, theconveyor may have a plurality of protruding panels being structured andarranged on the first section to push the product through the fluid inthe tank and being structured and arranged on the second section to liftthe product from the fluid in the tank to the second end of theconveyor. At least one first nozzle may be positioned substantiallyabove the first section of the conveyor and configured to deliver thefluid onto the product as the product is pushed by the plurality ofpanels. The fluid delivered from the at least one first nozzle mayrotate the product in the fluid in the tank.

In another embodiment of the present invention, a method of washing aproduct in a fluid includes the steps of introducing a plurality of theproduct into the fluid at a first position in a tank and pushing theplurality of product from the first position to a second position usinga plurality of protruding panels connected to a moving conveyor. Thefirst and second position may be substantially located in the fluid inthe tank. The method may also include the steps of rotating each of theplurality of product by delivering the fluid onto each of the pluralityof product from at least one first nozzle positioned between the firstposition and the second position and lifting the plurality of productfrom the second position to a third position where the third position isremoved from the fluid in the tank.

These and other objects and advantages of the invention will be apparentfrom the following description, the accompanying drawings and theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the present invention, it is believed the samewill be better understood from the following description taken inconjunction with the accompanying drawings, which illustrate, in anon-limiting fashion, the best mode presently contemplated for carryingout the present invention, and in which like reference numeralsdesignate like parts throughout the Figures, wherein:

FIG. 1 is a side view of an apparatus for washing a product according toone embodiment of the present invention;

FIG. 2 is a side view of a portion of the apparatus shown in FIG. 1according to one embodiment of the present invention;

FIG. 3 is a side view of another apparatus for washing a productaccording to an another embodiment of the present invention; and

FIG. 4 is a top view of the apparatus of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure will now be described more fully with referenceto the Figs. in which various embodiments of the present invention areshown. The subject matter of this disclosure may, however, be embodiedin many different forms and should not be construed as being limited tothe embodiments set forth herein.

One embodiment of the present invention includes an apparatus forproviding a positive means of removing soil, foreign matter, andbacteria from the surface of whole fruit and vegetables, particularlythose that float or have neutral bouyancy. It is contemplated thatelements, such as paddles, on a submerged conveyor belt may transportproduct through an array of spray nozzles. Fan shaped sprays may bealigned to form continuous transverse sheets of water, or other fluids,such that the sheets of water or other fluids impart a controlledrotating or spinning motion on the fruit.

In order to counteract the backward force of the sheets of water, theconveyor belt and the attached paddles or panels may be configured topush the floating product through the sprays. The spinning action of thefruit or vegetable ensures that the entire surface of the product isexposed water and cleaning solution. The spinning action also creates arelative velocity between the surfaces of the product and the water inwhich it is submerged, creating a scouring action on the surface of theproduct.

According to one embodiment of the present invention, the apparatus mayinclude a plurality of nozzles creating a plurality of continuous sheetsof water for the fruit to pass through, providing a thorough cleaning.After exiting the sprays, the conveyor belt may be configured to angleupward in order to carry the product out of the water bath. It iscontemplated that an additional set of fresh water sprays may be used torinse any cleaning solution and remaining residue that may be on theproduct. The final spray of fresh water may also function tocontinuously replenish the water in the bath with clean water.

According to one embodiment of the present invention, the washingapparatus may achieve an effective wash by utilizing the solventproperty of water to loosen and dissolve soil and foreign matter and byutilizing the impact from the sprays to physically loosen additionalsoil and contaminants adhering to the product. Additionally, the flow ofwater from the sprays into the bath may carry contaminants and bacteriaaway from the product body while chemical biocides and other cleaningsolutions known to those of skill in the art may kill any bacteriaremaining on the surface of the fruit or vegetable.

Contrary to the traditional cleaning methods, the present inventionincludes the use of a submerged conveyor with paddles to controlmovement of product through the array of sprays. Furthermore, thepresent invention uses high impact sprays to rotate and scour theproduct surface. It should be noted that, without the forward movementand force of the conveyor and submerged paddles, the impact force fromthe sprays used to rotate the product may be sufficient to halt forwardmovement of the product.

Referring to FIG. 1, a side view of a washing apparatus 100 according toan embodiment of the present invention is shown. The apparatus 100includes a water tank 5 into which products, including fruits andvegetables and other products, may be continuously loaded. As shown inFIG. 1 and used for illustrative purposes, apples are shown beingcontinuously loaded into the tank 5 to be washed. Once in the water ofthe tank 5, the apples may be propelled forward by jets of waterdischarging from nozzles 10 positioned across the rear wall of the tank5. Although only one nozzle 10 is shown in the side view of FIG. 1, itwould be apparent to those of skill in the art that various numbers ofnozzles 10 may be used to adequately move and direct the apples awayfrom the rear wall of the tank 5 as shown. Quick displacement of applesby the nozzles 10 reduces the possibility of collisions between applesbeing loaded and apples that are already floating in the water of thetank 5.

Within the tank 5, the apples may be directed by the water current fromthe nozzles 10 toward and onto a submerged horizontal conveyor 15 havingfull width paddles 20 at substantially regular intervals. In oneembodiment, the height of paddles 20 may be approximately 1.5 times theexpected diameter of product to be washed with the water level of thetank 5 maintained slightly above top of paddles 20.

As shown in FIG. 1, the paddles 20 may be configured to push thefloating apples forward into a series of transverse fan sprays createdby an array of nozzles 25. The array of nozzles 25 may be located onheader system 30 mounted over tank 5. As discussed above, the array ofnozzles may generate a continuous sheet of water delivered substantiallydownward from the arrays of nozzles 25. Upon impact with the apples orproduct, the sprays may cause the floating apples to rotate.

Referring to FIG. 2, the apples may usually first rotate forward in aclockwise direction, as shown by the arrows A, about their center ofgravity (shown as C.G. in FIG. 2) when the apple comes in contact withthe spray directed in the direction of arrow B. The paddles 20, movingin the direction of arrow C, may be used to force the apples into theline of spray. As a result of the forward movement of the paddle 20, theline of spray shown as arrow B will eventually move across the center ofgravity, causing the apple to rotate backward in a counterclockwisedirection. However, it should be understood that the rotation directionmay be reversed or changed without deviating from the scope and spiritof the present invention.

Referring again to FIG. 1, the apparatus 100 is shown with five sets ofarrays of nozzles 25. Each array of nozzles 25 causing this rotatingaction described with reference to FIG. 2. AS a result, the apparatus100 may generate significant scouring action between the movement androtation of the apple and the water in the tank 5. However, it should beunderstood that different types of arrangement and different numbers ofnozzles 25 may be used without deviating from the scope and spirit ofthe present invention.

After passing under the arrays of nozzles 25, the apples may be carriedor lifted out of the water of the tank 5 by the change in direction ofthe conveyor 15. Alternatively, a separate conveyor or other apparatusmay be used to remove the apples from the tank. As shown in FIG. 1, theconveyor 15 may incline upward after leaving washing zone and thenozzles 25, lifting the apples out of tank 5. The paddles 20 may also beused to prevent the apples from rolling back down the conveyor 15 andinto the tank 5. Furthermore, the paddles 20 may be employed to forcethe apples into a freshwater spray from a final array of nozzles 40. Thefreshwater spray may be used to rinse washer residue from the apples. Itis also contemplated that the freshwater spray may continuouslyreplenish the apparatus 100 with clean water. It should be notedhowever, that is a solution may be diluted by the addition of the freshwater from the nozzles 40.

Upon reaching the end of the conveyor 15, the apples may be collected orcarried away on additional conveyors (not shown) or other apparatusesaccording to convention means known in the art.

As shown in FIG. 1, the water supplied to tank from nozzles 10, 25, and40 may exit the tank 5 at the overflow passage 45. Water passing throughthe overflow passage 45 may initially collect in the first reservoir 50.Water overflowing the first reservoir 50 may passes through a sieve 55,allowing solid contaminants to be separated from the water. A secondreservoir 60 may be configured to collect the water that is ready to berecycled through the system.

Excess water supplied to system through freshwater spray may exit thesystem through an overflow port 65 located in the second reservoir 60. Acirculating pump 70 may be used to pump pressurized water back to thenozzles 10 and 25. As would be apparent to one of ordinary skill, thepump 70 may be sized and configured to produce the pressure needed todischarge water from the nozzles 10 and 25 at the desired velocity.Sand, sediment and other debris washed off the apples may settle in thebottom of the tank 5 or flow out of the tank through the overflowpassage 45. To aid in removing debris from the bottom of the tank 5, adrain valve 75 may be configured to release a large flow of waterthrough the drain valve 75 for a short increment of time.

Referring to FIGS. 3 and 4, another embodiment 200 of the washingapparatus is shown in accordance with the present invention. As shown,the conveyor 15 includes multiple sections are varying angles ofinclination. More particularly, the section of the conveyor nearest thenozzle 10 is angles downward and may allow the conveyor 15 to moreeasily load and gather product onto the conveyor 15 between the paddles20. The washing zone of the conveyor 15 is shown on the horizontal planeand positioned beneath the nozzles 25. Finally, upon leaving the washingzone, the conveyor 15 angles upward to carry or lift the washed productout of the tank 5, where the conveyor 15 levels off for a shortdistance. It should be understood that the configuration of theconveyor, including the length, width, and angle, may be changed withoutdeviating from the scope and spirit of the present invention.

As shown in the embodiment of FIGS. 3 and 4, the washing apparatusincludes multiple pumps 71 and 72 and also includes a filter 80 betweenthe pump 72 and the nozzles 25. The pump 72 may be associated with thenozzles 25 and sized and configured to produce pressurized water at thedesired pressure and volume flow. Likewise, the pump 71 may beassociated with nozzle 10 and may be configured to supply pressurizedwater to the nozzle 10 at a desired pressure. Alternative embodimentsand pump configurations may be considered and implemented withoutdeviation from the present invention.

Referring to FIG. 4, a top view of the washing apparatus 200 is shownwithout the conveyor in order to display the drive pulleys 85 and 90.The pulleys and the conveyor may be driven by a motor 95, which may besized and configured to move and lift the product through the tank 5 andout of the water after washing has occurred. It would be apparent tothose of skill in the art that the conveyor 15, drive pulleys 85 and 90,and the drive motor 95 may be implemented in many different ways and thefigures and descriptions should not be considered limiting on the scopeof the present invention.

It should be noted that the recirculating water system may be employedas shown in the embodiments of the present invention with water andother cleaning solutions. However, other fluids of varying consistenciesand viscosities may be used in accordance with the scope and spirit ofthe present invention. Likewise, as shown in FIG. 4, the header system30 includes three pipes distributing water to the nozzles 25. However,the header system 30 and the number and placement of nozzles 25 may bechanged without deviating from the scope and spirit of the presentinvention.

With reference to FIGS. 1-4, the embodiments of the present inventionhave been discussed with reference to water as the cleaning solutionemployed. However, it would be apparent to one of skill in the art thatother fluids, include solutions containing biocides and other cleaningsolutions, may be used. It should be noted that the use of chemicalsolutions in the tank and the fluid recirculation may be diluted overtime by the introduction of fresh water from the nozzles 40. As such, itis contemplated that the fresh water used for rinsing the product afteremerging from the tank, may be diverted from being collected by thetank. As such, the fresh water from nozzles 40 may not dilute thesolution in the tank 5 and the reservoirs 50 and 60.

The foregoing descriptions of specific embodiments of the presentinvention are presented for purposes of illustration and description.They are not intended to be exhaustive or to limit the invention to theprecise forms disclosed. Obviously, many modifications and variationsare possible in view of the above teachings. While the embodiments werechosen and described in order to best explain the principles of theinvention and its practical applications, thereby enabling othersskilled in the art to best utilize the invention, various embodimentswith various modifications as are suited to the particular use are alsopossible. The scope of the invention is to be defined only by the claimsappended hereto, and by their equivalents.

1. A method of washing a product in a fluid, the method comprising thesteps of: introducing a plurality of the product into a first end of atank containing a quantity of the fluid; propelling the product througha first distance from the first end of the tank toward a second end ofthe tank from which the product is extracted by using at least one firstnozzle discharging the fluid, the product floating at a top surface ofthe fluid in the tank and being disposed at a first position in the tankas a result of being propelled through the first distance; pushing thefloating product through a second distance from the first positiontoward the second end of the tank by using a plurality of protrudingpanels connected to a moving conveyor, the plurality of protrudingpanels being substantially disposed in the fluid in the tank, a portionof each of the floating product protruding above the top surface of thefluid in the tank, the floating product being disposed at a secondposition in the tank as a result of being pushed through the seconddistance; impacting the protruding portion of each of the product with aflow of the fluid from at least one second nozzle positioned between thefirst and second positions; and extracting the product from the secondend of the tank.
 2. The method according to claim 1, further comprisingthe step of delivering fresh water to the product from at least onethird nozzle after the product are extracted from the second end of thetank.
 3. The method according to claim 2, further comprising the stepsof: removing a portion of the fluid from the tank through an overflowpassage connected to the tank; and collecting the portion of the fluidin a reservoir configured to receive the fluid from the overflowpassage.
 4. The method according to claim 3, further comprising the stepof filtering the portion of the fluid using at least one of a filter ora sieve positioned between the overflow passage and the reservoir. 5.The method according to claim 3, further comprising the step of pumpingthe portion of the fluid from the reservoir to the at least one firstnozzle and the at least one second nozzle.
 6. The method according toclaim 3, further comprising the step of filtering the portion of thefluid using a filter positioned between the reservoir and at least oneof the at least one first nozzle or the at least one second nozzle. 7.The method according to claim 1, wherein the flow of fluid impacting theprotruding portion of each of the plurality of product comprises atleast one sheet of water oriented traverse to the movement direction ofthe floating product.
 8. The method according to claim 1, wherein theflow of fluid impacting the protruding portion of each of the pluralityof products causes at least one of the floating product to rotate. 9.The method according to claim 1, wherein: the product are introducedinto the first end of the tank in a continuous fashion; and the at leastone first nozzle propels the product to reduce the possibility ofcollision between product already floating in the tank and product beingintroduced into the first end of the tank.
 10. The method according toclaim 1, wherein: the at least one second nozzle comprises a pluralityof arrays of second nozzles; and each array of second nozzles generatesa sheet of water oriented traverse to the movement direction of thefloating product and configured to impact the protruding portions of thefloating product.
 11. The method according to claim 1, furthercomprising capturing the product floating into the first position with asubmerged inclined portion of the moving conveyor.
 12. The methodaccording to claim 11, wherein the at least one first nozzle comprises aplurality of first nozzles distributed along the first end of the tank.